/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2008-02-22     QiuYi        The first version.
 * 2011-10-08     Bernard      fixed the block size in statfs.
 * 2011-11-23     Bernard      fixed the rename issue.
 */

#include <rtthread.h>
#include "ffconf.h"
#include "ff.h"

/* ELM FatFs provide a DIR struct */
#define HAVE_DIR_STRUCTURE

#include <dfs_fs.h>
#include <dfs.h>

#ifdef DFS_ELMFAT_INTERFACE_EFM
#include "diskio.h"

/* Disk status */
static volatile DSTATUS diskStat[_VOLUMES];
#endif
static rt_device_t disk[_VOLUMES] = {0};

static int elm_result_to_dfs(FRESULT result)
{
    int status = DFS_STATUS_OK;

    switch (result)
    {
    case FR_OK:
        break;

    case FR_NO_FILE:
    case FR_NO_PATH:
    case FR_NO_FILESYSTEM:
        status = -DFS_STATUS_ENOENT;
        break;

    case FR_INVALID_NAME:
        status = -DFS_STATUS_EINVAL;
        break;

    case FR_EXIST:
    case FR_INVALID_OBJECT:
        status = -DFS_STATUS_EEXIST;
        break;

    case FR_DISK_ERR:
    case FR_NOT_READY:
    case FR_INT_ERR:
        status = -DFS_STATUS_EIO;
        break;

    case FR_WRITE_PROTECTED:
    case FR_DENIED:
        status = -DFS_STATUS_EROFS;
        break;

    case FR_MKFS_ABORTED:
        status = -DFS_STATUS_EINVAL;
        break;

    default:
        status = -1;
        break;
    }

    return status;
}

int dfs_elm_mount(struct dfs_filesystem *fs, unsigned long rwflag, const void *data)
{
    FATFS *fat;
    FRESULT result;
    rt_uint32_t index;

    /* handle RT-Thread device routine */
    for (index = 0; index < _VOLUMES; index ++)
    {
        if (disk[index] == RT_NULL)
        {
            break;
        }
    }
    if (index == _VOLUMES)
        return -DFS_STATUS_ENOSPC;

    /* get device */
    disk[index] = fs->dev_id;

    fat = (FATFS *)rt_malloc(sizeof(FATFS));
    if (fat == RT_NULL)
    {
        return -1;
    }

    /* mount fatfs, always 0 logic driver */
    result = f_mount(index, fat);
    if (result == FR_OK)
        fs->data = fat;
    else
    {
        rt_free(fat);
        return elm_result_to_dfs(result);
    }

    return 0;
}

int dfs_elm_unmount(struct dfs_filesystem *fs)
{
    FATFS *fat;
    FRESULT result;
    rt_uint32_t index;

    fat = (FATFS *)fs->data;

    RT_ASSERT(fat != RT_NULL);

    /* find the device index and then umount it */
    for (index = 0; index < _VOLUMES; index ++)
    {
        if (disk[index] == fs->dev_id)
        {
            result = f_mount(index, RT_NULL);

            if (result == FR_OK)
            {
                fs->data = RT_NULL;
                disk[index] = RT_NULL;
                rt_free(fat);
                return DFS_STATUS_OK;
            }
        }
    }

    return -DFS_STATUS_ENOENT;
}

int dfs_elm_mkfs(const char *device_name)
{
    BYTE drv;
    rt_device_t dev;
    FRESULT result;

    /* find device name */
    for (drv = 0; drv < _VOLUMES; drv ++)
    {
        dev = disk[drv];
        if (rt_strncmp(dev->parent.name, device_name, RT_NAME_MAX) == 0)
        {
            /* 1: no partition table */
            /* 0: auto selection of cluster size */
            result = f_mkfs(drv, 1, 0);
            if (result != FR_OK)
            {
                rt_kprintf("format error\n");
                return elm_result_to_dfs(result);
            }

            return DFS_STATUS_OK;
        }
    }

    /* can't find device driver */
    rt_kprintf("can not find device driver: %s\n", device_name);
    return -DFS_STATUS_EIO;
}

int dfs_elm_statfs(struct dfs_filesystem *fs, struct statfs *buf)
{
    FATFS *f;
    FRESULT res;
    char driver[4];
    DWORD fre_clust, fre_sect, tot_sect;

    RT_ASSERT(fs != RT_NULL);
    RT_ASSERT(buf != RT_NULL);

    f = (FATFS *)fs->data;

    rt_snprintf(driver, sizeof(driver), "%d:", f->drv);
    res = f_getfree(driver, &fre_clust, &f);
    if (res)
        return elm_result_to_dfs(res);

    /* Get total sectors and free sectors */
    tot_sect = (f->n_fatent - 2) * f->csize;
    fre_sect = fre_clust * f->csize;

    buf->f_bfree = fre_sect;
    buf->f_blocks = tot_sect;
#if _MAX_SS != 512
    buf->f_bsize = f->ssize;
#else
    buf->f_bsize = 512;
#endif

    return 0;
}

int dfs_elm_open(struct dfs_fd *file)
{
    FIL *fd;
    BYTE mode;
    FRESULT result;
    char *drivers_fn;

#if (_VOLUMES > 1)
    int vol;
    extern int elm_get_vol(FATFS *fat);

    /* add path for ELM FatFS driver support */
    vol = elm_get_vol((FATFS *)file->fs->data);
    if (vol < 0)
        return -DFS_STATUS_ENOENT;
    drivers_fn = rt_malloc(256);
    if (drivers_fn == RT_NULL)
        return -DFS_STATUS_ENOMEM;

    rt_snprintf(drivers_fn, 256, "%d:%s", vol, file->path);
#else
    drivers_fn = file->path;
#endif

    if (file->flags & DFS_O_DIRECTORY)
    {
        DIR *dir;

        if (file->flags & DFS_O_CREAT)
        {
            result = f_mkdir(drivers_fn);
            if (result != FR_OK)
            {
#if _VOLUMES > 1
                rt_free(drivers_fn);
#endif
                return elm_result_to_dfs(result);
            }
        }

        /* open directory */
        dir = (DIR *)rt_malloc(sizeof(DIR));
        if (dir == RT_NULL)
        {
#if _VOLUMES > 1
            rt_free(drivers_fn);
#endif
            return -DFS_STATUS_ENOMEM;
        }

        result = f_opendir(dir, drivers_fn);
#if _VOLUMES > 1
        rt_free(drivers_fn);
#endif
        if (result != FR_OK)
        {
            rt_free(dir);
            return elm_result_to_dfs(result);
        }

        file->data = dir;
        return DFS_STATUS_OK;
    }
    else
    {
        mode = FA_READ;

        if (file->flags & DFS_O_WRONLY)
            mode |= FA_WRITE;
        if ((file->flags & DFS_O_ACCMODE) & DFS_O_RDWR)
            mode |= FA_WRITE;
        /* Opens the file, if it is existing. If not, a new file is created. */
        if (file->flags & DFS_O_CREAT)
            mode |= FA_OPEN_ALWAYS;
        /* Creates a new file. If the file is existing, it is truncated and overwritten. */
        if (file->flags & DFS_O_TRUNC)
            mode |= FA_CREATE_ALWAYS;
        /* Creates a new file. The function fails if the file is already existing. */
        if (file->flags & DFS_O_EXCL)
            mode |= FA_CREATE_NEW;

        /* allocate a fd */
        fd = (FIL *)rt_malloc(sizeof(FIL));
        if (fd == RT_NULL)
        {
            return -DFS_STATUS_ENOMEM;
        }

        result = f_open(fd, drivers_fn, mode);
#if _VOLUMES > 1
        rt_free(drivers_fn);
#endif
        if (result == FR_OK)
        {
            file->pos  = fd->fptr;
            file->size = fd->fsize;
            file->data = fd;

            if (file->flags & DFS_O_APPEND)
            {
                file->pos = f_lseek(fd, fd->fsize);
            }
        }
        else
        {
            /* open failed, return */
            rt_free(fd);
            return elm_result_to_dfs(result);
        }
    }

    return DFS_STATUS_OK;
}

int dfs_elm_close(struct dfs_fd *file)
{
    FRESULT result;

    result = FR_OK;
    if (file->type == FT_DIRECTORY)
    {
        DIR *dir;

        dir = (DIR *)(file->data);
        RT_ASSERT(dir != RT_NULL);

        /* release memory */
        rt_free(dir);
    }
    else if (file->type == FT_REGULAR)
    {
        FIL *fd;
        fd = (FIL *)(file->data);
        RT_ASSERT(fd != RT_NULL);

        result = f_close(fd);
        if (result == FR_OK)
        {
            /* release memory */
            rt_free(fd);
        }
    }

    return elm_result_to_dfs(result);
}

int dfs_elm_ioctl(struct dfs_fd *file, int cmd, void *args)
{
    return -DFS_STATUS_ENOSYS;
}

int dfs_elm_read(struct dfs_fd *file, void *buf, rt_size_t len)
{
    FIL *fd;
    FRESULT result;
    UINT byte_read;

    if (file->type == FT_DIRECTORY)
    {
        return -DFS_STATUS_EISDIR;
    }

    fd = (FIL *)(file->data);
    RT_ASSERT(fd != RT_NULL);

    result = f_read(fd, buf, len, &byte_read);
    /* update position */
    file->pos  = fd->fptr;
    if (result == FR_OK)
        return byte_read;

    return elm_result_to_dfs(result);
}

int dfs_elm_write(struct dfs_fd *file, const void *buf, rt_size_t len)
{
    FIL *fd;
    FRESULT result;
    UINT byte_write;

    if (file->type == FT_DIRECTORY)
    {
        return -DFS_STATUS_EISDIR;
    }

    fd = (FIL *)(file->data);
    RT_ASSERT(fd != RT_NULL);

    result = f_write(fd, buf, len, &byte_write);
    /* update position and file size */
    file->pos  = fd->fptr;
    file->size = fd->fsize;
    if (result == FR_OK)
        return byte_write;

    return elm_result_to_dfs(result);
}

int dfs_elm_flush(struct dfs_fd *file)
{
    FIL *fd;
    FRESULT result;

    fd = (FIL *)(file->data);
    RT_ASSERT(fd != RT_NULL);

    result = f_sync(fd);
    return elm_result_to_dfs(result);
}

int dfs_elm_lseek(struct dfs_fd *file, rt_off_t offset)
{
    FRESULT result = FR_OK;
    if (file->type == FT_REGULAR)
    {
        FIL *fd;

        /* regular file type */
        fd = (FIL *)(file->data);
        RT_ASSERT(fd != RT_NULL);

        result = f_lseek(fd, offset);
        if (result == FR_OK)
        {
            /* return current position */
            return fd->fptr;
        }
    }
    else if (file->type == FT_DIRECTORY)
    {
        /* which is a directory */
        DIR *dir;

        dir = (DIR *)(file->data);
        RT_ASSERT(dir != RT_NULL);

        result = f_seekdir(dir, offset / sizeof(struct dirent));
        if (result == FR_OK)
        {
            /* update file position */
            file->pos = offset;
            return file->pos;
        }
    }

    return elm_result_to_dfs(result);
}

int dfs_elm_getdents(struct dfs_fd *file, struct dirent *dirp, rt_uint32_t count)
{
    DIR *dir;
    FILINFO fno;
    FRESULT result;
    rt_uint32_t index;
    struct dirent *d;

    dir = (DIR *)(file->data);
    RT_ASSERT(dir != RT_NULL);

    /* make integer count */
    count = (count / sizeof(struct dirent)) * sizeof(struct dirent);
    if (count == 0)
        return -DFS_STATUS_EINVAL;

#if _USE_LFN
    /* allocate long file name */
    fno.lfname = rt_malloc(256);
    fno.lfsize = 256;
#endif

    index = 0;
    while (1)
    {
        char *fn;

        d = dirp + index;

        result = f_readdir(dir, &fno);
        if (result != FR_OK || fno.fname[0] == 0)
            break;

#if _USE_LFN
        fn = *fno.lfname? fno.lfname : fno.fname;
#else
        fn = fno.fname;
#endif

        d->d_type = DFS_DT_UNKNOWN;
        if (fno.fattrib & AM_DIR)
            d->d_type = DFS_DT_DIR;
        else
            d->d_type = DFS_DT_REG;

        d->d_namlen = rt_strlen(fn);
        d->d_reclen = (rt_uint16_t)sizeof(struct dirent);
        rt_strncpy(d->d_name, fn, rt_strlen(fn) + 1);

        index ++;
        if (index * sizeof(struct dirent) >= count)
            break;
    }

#if _USE_LFN
    rt_free(fno.lfname);
#endif

    if (index == 0)
        return elm_result_to_dfs(result);

    file->pos += index * sizeof(struct dirent);

    return index * sizeof(struct dirent);
}

int dfs_elm_unlink(struct dfs_filesystem *fs, const char *path)
{
    FRESULT result;

#if _VOLUMES > 1
    int vol;
    char *drivers_fn;
    extern int elm_get_vol(FATFS *fat);

    /* add path for ELM FatFS driver support */
    vol = elm_get_vol((FATFS *)fs->data);
    if (vol < 0)
        return -DFS_STATUS_ENOENT;
    drivers_fn = rt_malloc(256);
    if (drivers_fn == RT_NULL)
        return -DFS_STATUS_ENOMEM;

    rt_snprintf(drivers_fn, 256, "%d:%s", vol, path);
#else
    const char *drivers_fn;
    drivers_fn = path;
#endif

    result = f_unlink(drivers_fn);
#if _VOLUMES > 1
    rt_free(drivers_fn);
#endif
    return elm_result_to_dfs(result);
}

int dfs_elm_rename(struct dfs_filesystem *fs, const char *oldpath, const char *newpath)
{
    FRESULT result;

#if _VOLUMES > 1
    char *drivers_oldfn;
    const char *drivers_newfn;
    int vol;
    extern int elm_get_vol(FATFS *fat);

    /* add path for ELM FatFS driver support */
    vol = elm_get_vol((FATFS *)fs->data);
    if (vol < 0)
        return -DFS_STATUS_ENOENT;

    drivers_oldfn = rt_malloc(256);
    if (drivers_oldfn == RT_NULL)
        return -DFS_STATUS_ENOMEM;
    drivers_newfn = newpath;

    rt_snprintf(drivers_oldfn, 256, "%d:%s", vol, oldpath);
#else
    const char *drivers_oldfn, *drivers_newfn;

    drivers_oldfn = oldpath;
    drivers_newfn = newpath;
#endif

    result = f_rename(drivers_oldfn, drivers_newfn);
#if _VOLUMES > 1
    rt_free(drivers_oldfn);
#endif
    return elm_result_to_dfs(result);
}

int dfs_elm_stat(struct dfs_filesystem *fs, const char *path, struct stat *st)
{
    FILINFO file_info;
    FRESULT result;


#if _VOLUMES > 1
    int vol;
    char *drivers_fn;
    extern int elm_get_vol(FATFS *fat);

    /* add path for ELM FatFS driver support */
    vol = elm_get_vol((FATFS *)fs->data);
    if (vol < 0)
        return -DFS_STATUS_ENOENT;
    drivers_fn = rt_malloc(256);
    if (drivers_fn == RT_NULL)
        return -DFS_STATUS_ENOMEM;

    rt_snprintf(drivers_fn, 256, "%d:%s", vol, path);
#else
    const char *drivers_fn;
    drivers_fn = path;
#endif

#if _USE_LFN
    /* allocate long file name */
    file_info.lfname = rt_malloc(256);
    file_info.lfsize = 256;
#endif

    result = f_stat(drivers_fn, &file_info);
#if _VOLUMES > 1
    rt_free(drivers_fn);
#endif
    if (result == FR_OK)
    {
        /* convert to dfs stat structure */
        st->st_dev = 0;

        st->st_mode = DFS_S_IFREG | DFS_S_IRUSR | DFS_S_IRGRP | DFS_S_IROTH |
        DFS_S_IWUSR | DFS_S_IWGRP | DFS_S_IWOTH;
        if (file_info.fattrib & AM_DIR)
        {
            st->st_mode &= ~DFS_S_IFREG;
            st->st_mode |= DFS_S_IFDIR | DFS_S_IXUSR | DFS_S_IXGRP | DFS_S_IXOTH;
        }
        if (file_info.fattrib & AM_RDO)
            st->st_mode &= ~(DFS_S_IWUSR | DFS_S_IWGRP | DFS_S_IWOTH);

        st->st_size  = file_info.fsize;
        st->st_mtime = file_info.ftime;
    }

#if _USE_LFN
    rt_free(file_info.lfname);
#endif

    return elm_result_to_dfs(result);
}

static const struct dfs_filesystem_operation dfs_elm =
{
    "elm",
    dfs_elm_mount,
    dfs_elm_unmount,
    dfs_elm_mkfs,
    dfs_elm_statfs,

    dfs_elm_open,
    dfs_elm_close,
    dfs_elm_ioctl,
    dfs_elm_read,
    dfs_elm_write,
    dfs_elm_flush,
    dfs_elm_lseek,
    dfs_elm_getdents,
    dfs_elm_unlink,
    dfs_elm_stat,
    dfs_elm_rename,
};

int elm_init(void)
{
#ifdef DFS_ELMFAT_INTERFACE_EFM
    int i;

    for (i = 0; i < _VOLUMES; i++)
    {
        diskStat[i] = STA_NOINIT;
    }
#endif

    /* register fatfs file system */
    dfs_register(&dfs_elm);

    return 0;
}

/*
 * RT-Thread Device Interface for ELM FatFs
 */
#ifdef DFS_ELMFAT_INTERFACE_EFM
/*-----------------------------------------------------------------------*/
/* Initialize Disk Drive                                                 */
/*-----------------------------------------------------------------------*/
DSTATUS disk_initialize (
    BYTE drv                /* Physical drive nmuber */
    )
{
    rt_device_t device = disk[drv];

    if (!device)
    {
        return RES_ERROR;
    }
    if (diskStat[drv] & STA_NODISK)
    {
        /* No card in the socket */
        return diskStat[drv];
    }

    /* Initialize hardware: the actual operation is performed in dfs_mount() */
    diskStat[drv] &= ~STA_NOINIT;

    return diskStat[drv];
}

/*-----------------------------------------------------------------------*/
/* Get Disk Status                                                       */
/*-----------------------------------------------------------------------*/
DSTATUS disk_status (
    BYTE drv                /* Physical drive nmuber */
    )
{
    return diskStat[drv];
}

/*-----------------------------------------------------------------------*/
/* Read Sector(s)                                                        */
/*-----------------------------------------------------------------------*/
DRESULT disk_read (
    BYTE drv,               /* Physical drive nmuber */
    BYTE *buff,             /* Pointer to the data buffer to store read data */
    DWORD sector,           /* Start sector number (LBA) */
    BYTE count              /* Sector count (1..255) */
    )
{
    rt_device_t device = disk[drv];

    if (!device)
    {
        return RES_ERROR;
    }
    if (!count)
    {
        return RES_PARERR;
    }
    if (diskStat[drv] & STA_NOINIT)
    {
        return RES_NOTRDY;
    }

    if (rt_device_read(device, sector, buff, count) != count)
    {
        return RES_ERROR;
    }
    else
    {
        return RES_OK;
    }
}

/*-----------------------------------------------------------------------*/
/* Write Sector(s)                                                       */
/*-----------------------------------------------------------------------*/
#if _READONLY == 0
DRESULT disk_write (
    BYTE drv,               /* Physical drive nmuber */
    const BYTE *buff,       /* Pointer to the data to be written */
    DWORD sector,           /* Start sector number (LBA) */
    BYTE count              /* Sector count (1..255) */
    )
{
    rt_device_t device = disk[drv];

    if (!device)
    {
        return RES_ERROR;
    }
    if (!count)
    {
        return RES_PARERR;
    }
    if (diskStat[drv] & STA_NOINIT)
    {
        return RES_NOTRDY;
    }
    if (diskStat[drv] & STA_PROTECT)
    {
        return RES_WRPRT;
    }

    if (rt_device_write(device, sector, buff, count) != count)
    {
        return RES_ERROR;
    }
    else
    {
        return RES_OK;
    }
}
#endif /* _READONLY */

/*-----------------------------------------------------------------------*/
/* Miscellaneous Functions                                               */
/*-----------------------------------------------------------------------*/
DRESULT disk_ioctl (
    BYTE drv,       /* Physical drive nmuber */
    BYTE ctrl,      /* Control code */
    void *buff      /* Buffer to send/receive data block */
)
{
    rt_device_t device = disk[drv];

    if (!device)
    {
        return RES_ERROR;
    }
    if (diskStat[drv] & STA_NOINIT)
    {
        return RES_NOTRDY;
    }

    if (rt_device_control(device, ctrl, buff) != RT_EOK)
    {
        return RES_ERROR;
    }
    else
    {
        return RES_OK;
    }
}
#else
#include "diskio.h"

/* Inidialize a Drive */
DSTATUS disk_initialize(BYTE drv)
{
    return 0;
}

/* Return Disk Status */
DSTATUS disk_status(BYTE drv)
{
    return 0;
}

/* Read Sector(s) */
DRESULT disk_read(BYTE drv, BYTE *buff, DWORD sector, BYTE count)
{
    rt_size_t result;
    rt_device_t device = disk[drv];

    result = rt_device_read(device, sector, buff, count);
    if (result == count)
    {
        return RES_OK;
    }

    return RES_ERROR;
}

/* Write Sector(s) */
DRESULT disk_write(BYTE drv, const BYTE *buff, DWORD sector, BYTE count)
{
    rt_size_t result;
    rt_device_t device = disk[drv];

    result = rt_device_write(device, sector, buff, count);
    if (result == count)
    {
        return RES_OK;
    }

    return RES_ERROR;
}

/* Miscellaneous Functions */
DRESULT disk_ioctl(BYTE drv, BYTE ctrl, void *buff)
{
    rt_device_t device = disk[drv];

    if (device == RT_NULL)
        return RES_ERROR;

    if (ctrl == GET_SECTOR_COUNT)
    {
        struct rt_device_blk_geometry geometry;

        rt_memset(&geometry, 0, sizeof(geometry));
        rt_device_control(device, RT_DEVICE_CTRL_BLK_GETGEOME, &geometry);

        *(DWORD *)buff = geometry.sector_count;
        if (geometry.sector_count == 0)
            return RES_ERROR;
    }
    else if (ctrl == GET_SECTOR_SIZE)
    {
        struct rt_device_blk_geometry geometry;

        rt_memset(&geometry, 0, sizeof(geometry));
        rt_device_control(device, RT_DEVICE_CTRL_BLK_GETGEOME, &geometry);

        *(WORD *)buff = geometry.bytes_per_sector;
    }
    else if (ctrl == GET_BLOCK_SIZE) /* Get erase block size in unit of sectors (DWORD) */
    {
        struct rt_device_blk_geometry geometry;

        rt_memset(&geometry, 0, sizeof(geometry));
        rt_device_control(device, RT_DEVICE_CTRL_BLK_GETGEOME, &geometry);

        *(DWORD *)buff = geometry.block_size/geometry.bytes_per_sector;
    }

    return RES_OK;
}
#endif

rt_time_t get_fattime(void)
{
    return 0;
}

#if _FS_REENTRANT
int ff_cre_syncobj(BYTE drv, _SYNC_t *m)
{
    char name[8];
    rt_mutex_t mutex;

    rt_snprintf(name, sizeof(name), "fat%d", drv);
    mutex = rt_mutex_create(name, RT_IPC_FLAG_FIFO);
    if (mutex != RT_NULL)
    {
        *m = mutex;
        return RT_TRUE;
    }

    return RT_FALSE;
}

int ff_del_syncobj(_SYNC_t m)
{
    rt_mutex_delete(m);

    return RT_TRUE;
}

int ff_req_grant(_SYNC_t m)
{
    if (rt_mutex_take(m, _FS_TIMEOUT) == RT_EOK)
        return RT_TRUE;

    return RT_FALSE;
}

void ff_rel_grant(_SYNC_t m)
{
    rt_mutex_release(m);
}

#endif
